In my previous U.S. Pat. No. 4,993,124 issued on Feb. 19, 1991, I disclose a worm drive clamp of a construction wherein the free end portion of the flexible metal clamping band is spring-biased against a tightening screw which is axially rotatable on a fixed axis. The advantages of being able to insert the band through the housing without engagement with the threaded screw is disclosed therein. Another advantage is to easily and quickly insert the free end portion of the band within the housing and providing engagement of the screw only after the band has completely encircled the object which is to be secured thereto. This desirable feature provides for the clamp to be quickly connected and disconnected from an object.
The present invention is directed to a worm drive clamp of the type wherein the tightening screw is hingeably secured within the housing and can be hinged out of engagement with the free end portion of the band. Such clamps are known in the art, such as that described and shown in U.S. Pat No. 2,825,113 issued on Mar. 4, 1958 and U.S. Pat. No. 4,445,254 issued on May 1, 1984. As described in these patents the tightening screw is displaceable both in the axial direction and upwardly away from the free end portion of the band which is passed through the housing. A disadvantage of these clamps is that the tightening screw provides obstruction to the free end portion of the band when inserted in the housing. When the band is inserted in the housing it moves upwardly towards the screw due to the arcuate shape of the band and also due to the fact that the passage provides for the band to spring upwardly therein. In other words, the band enters one end of the housing and out the other without any guided restriction between the opposed ends of the passage. This is due to the fact that the screw has to move upwards and downwards in the housing. The construction of these clamps also makes it very difficult to restrict the passage of the band within the housing. Accordingly, many of these types of clamps have not achieved commercial success. These clamps also have various component parts and are difficult to assemble, and often resulting in malfunction.
U.S. Pat. No. 4,307,495 discloses a housing with opposed guide channels for positioning the free end portion of a flexible band in contact with a tightening screw. However, such is difficult and complex to manufacture, and the screw is maintained at a fixed position. Such complexity becomes compounded when the bottom wall of the housing has an arcuate shape.